A vacant 239 Greenwich Ave., the former home of Restoration Hardware, Greenwich, Conn., Wednesday, June 18, 2014. Restoration Hardware has moved to the building that formerly housed the U.S. Post Office on Greenwich Avenue.

There are fewer vacant storefronts on Greenwich Avenue than since the start of the recession six years ago, and the owners of a Hartford restaurant have been watching.

They realized that if they didn't act soon, an appropriate space might not be available, so they signed a lease for a 1,600-square-foot space at 401 Greenwich Ave., with the goal of opening Yogurt City by early August.

"I think there's a lot of potential in a yogurt place on Greenwich Avenue. There's something special about Greenwich," said Tiffany Cheng, whose family owns the Lok Chung restaurant in Hartford.

Formerly occupied by a sweets shop called Sweet Teez, the space was represented by Marshall Heaven, principal in M.H. Heaven Real Estate in Greenwich, which also represents properties at 10 and 26 Greenwich Ave.

"Greenwich Avenue is doing much better," Heaven said. "We turned the corner about 1½ years ago. We had about 20 vacancies. There are less than 10 now. We're seeing fewer tenants leaving. I'm very optimistic."

Retail space on the avenue, which could be compared to an outdoor shopping mall, is going for $50 to $160 per square foot, with lower-priced space impacted by physical constraints, according to Heaven, who has been a commercial real estate broker in Greenwich since 1977.

There has been less need for landlords to offer inducements during lease negotiations as space availability tightens, Heaven said, adding that there has been more interest in 26 Greenwich Ave., than in the past six months, and there have been discussions about 10 Greenwich Ave.

"We're narrowing in on a deal," he said.

There also has been intense interest in space at 239 Greenwich Ave., occupied by Restoration Hardware before its move to the refurbished former post office building at 310 Greenwich Ave., according to Jessica Curtis, senior managing director at the Greenwich office of Newmark Grubb Knight Frank.

A dozen prospective occupants have looked at the 12,293-square-foot space spread over two levels, according to Curtis.

"It's a premier corner space. The property is in a word, stunning. Retailers seeking opportunities on the avenue have always been drawn to its dramatic corner presence, extensive window line and classic architecture," said Curtis, who also represents space at 200 and 409 Greenwich Ave.

The building at 239 Greenwich Ave., where Restoration Hardware was located for 16 years, is owned by Acadia Realty Trust and Aberdeen Properties.

"This is the 50-yard line of the avenue, in the same block as Ralph Lauren and Hermes," said Christopher Conlon, executive vice president and CEO of Acadia, in a statement. "It's a stately building that offers space that simply doesn't exist anywhere else on Greenwich Avenue."

Curtis attributed some of the improvement in rental activity to growing confidence in the economy. "The vacancy rate (on Greenwich Avenue) has dropped significantly. The street is vibrant with activity. Spending is up. The financial services industry -- the base of Greenwich -- has strengthened. International and national retailers are looking to expand," Curtis said, adding that the arrival last year of Hermes, the upscale international lifestyle, clothing and accessory retailer, helped stimulate interest in available space on the avenue.

Tom Torelli, managing partner in Allied Property Group, has partnered in Laraco 376, a group that is so confident in the future of the avenue that it is building a 12,300-square-foot retail/office/residential building at 376 Greenwich Ave., and it already has leases with three commercial tenants.

"There's a huge difference from 2008-2009 when we had 21 vacancies. By 2013, that excess inventory had been burned off. We have about 130 storefronts on Greenwich Avenue," said Torelli, who expects to remove a for-rent sign soon from 173 Greenwich Ave., where Club Monaco, a division of Ralph Lauren, plans to open in a 3,234-square-foot space in the fall.

"They're an upscale J. Crew. I generally leave the sign in the window until the tenant starts doing work," said Torelli, noting that Shreve, Crump &Low, a Boston-based upscale jeweler, will be moving into 125 Greenwich Ave., in the fall.

"We're under what our normal inventory is," he said, "and back to pre-recession prices."